github actions + goreleaser to build and publish binaries (#1623)

* initial github action to build github hosted binary artifact releases

* consistent with Makefile

* fix syntax error

* add GOPROXY env var

* reintroduce VERSION to env and go build.version

* barf, typo

* set build.version to the tag

Co-authored-by: Aaron Schlesinger <70865+arschles@users.noreply.github.com>

.goreleaser.yml

@@ -0,0 +1,29 @@
+before:
+  hooks:
+    - go mod download
+env:
+- CGO_ENABLED=0
+- GOPROXY=https://proxy.golang.org
+project_name: athens
+builds:
+- id: builds
+  goos:
+    - linux
+    - darwin
+  goarch:
+    - amd64
+  main: cmd/proxy/main.go
+  binary: athens
+  ldflags:
+    - -X "github.com/gomods/athens/pkg/build.version={{ .Tag }}"
+    - -X "github.com/gomods/athens/pkg/build.buildDate={{ .Env.DATE }}"
+checksum:
+  name_template: 'checksums.txt'
+snapshot:
+  name_template: "{{ .Tag }}-next"
+changelog:
+  sort: asc
+  filters:
+    exclude:
+    - '^docs:'
+    - '^test:'